, a '''mutation''' is the permanent alteration of the base sequence|nucleotide sequence
of the genome
of an organism
, or extrachromosomal DNA
or other genetic elements.
Mutations result from errors during DNA replication
or other types of damage to DNA
, which then may undergo error-prone repair (especially microhomology-mediated end joining
), or cause an error during other forms of repair,
or else may cause an error during replication (DNA repair#Translesion synthesis|translesion synthesis
). Mutations may also result from Insertion (genetics)|insertion
or Deletion (genetics)|deletion
of segments of DNA due to mobile genetic elements
Mutations may or may not produce discernible changes in the...